Principle and structure of 1.

Charles filter is an optical filter that only allows red light and part of yellow-green light to pass through. Observing objects through Charles filter, all objects will only have two colors: red or yellow-green.

Emerald contains chromium ions, which can emit red fluorescence under visible light or ultraviolet light, and appear red or pink under Charles filter. However, other green gemstones without chromium ions do not fluoresce and are green under the Charles filter. From this, emerald and its imitation can be distinguished, so it is also called emerald mirror.

use

1. Distinguish emeralds from their imitations.

Emeralds are usually red or pink under the Charles filter. However, the emeralds in South Africa will not turn red under the Charles filter.

4. Detection of artificial materials stained with cobalt.

Artificial materials colored with cobalt, such as synthetic blue spinel, synthetic blue time, cobalt glass, etc. Under the Charles filter, they all show different shades of red. Imitation imitation sapphire, aquamarine, blue topaz and natural blue spinel do not change color.

3. Detect the dyed jadeite.

Jadeite dyed with chromium salt will turn red under Charles filter, while natural jadeite dyed without chromium salt will not turn red.

4. Distinguish between natural chrysotile (colored by nickel) and dyed chrysotile.

Dyed chrysotile turns red under Charles filter, while natural chrysotile (colored by nickel) does not change color.